COMPOSITIONAL MAPPING BY LASER-INDUCED BREAKDOWN SPECTROSCOPY

A sensitive optical technique for compositional mapping of solid surfa ces using laser-induced breakdown spectroscopy (LIBS) is described. A pulsed Nd:YAG laser with second harmonic module was focused on the sol id surface, giving a small ablation area, to produce plasma emission. Copper and magnesium emissions from a standard sample were carefully a nalyzed and assigned in the wavelength range 500-520 nm. The assigned spectral information was selected to construct an image of 100 x 100 p ixels by mapping the measured emission intensity values from the analy zed points. The time required for image construction and image sharpne ss depends on the number of laser shots per point of analysis and the number of analyzed points per image. A clear image of a copper conduct or pattern from a printed circuit board was generated. In addition, so me copper contaminations around the conductor area are clearly visible in the scanning LIES map. The contaminated copper salt probably resul ted from the incomplete washing step during manufacturing that could c ause a short circuit in an electronic device.